Composite tubing coupling with corrosion resistance and heat preservation performance

Abstract

The utility model relates to the technical field of oil and gas field exploitation, in particular to a composite tubing coupling with corrosion resistance and thermal insulation performance, which comprises a coupling inner tube, a hydrogen absorption coating, a thermal insulation layer and a coupling outer tube, the coupling inner tube is cylindrical, and the hydrogen absorption coating is coated on the outer wall surface of the coupling inner tube; the outer wall of the hydrogen absorption coating is coated with the heat preservation layer; the coupling outer pipe is cylindrical and is connected to the outer wall face of the heat preservation layer in a sleeving mode, and a laser cladding coating is arranged on the outer wall face of the coupling outer pipe. The section of an inner hole of the coupling inner pipe is in a symmetrical step shape, and the two ends of the inner hole of the coupling inner pipe are sequentially provided with heat insulation spraying sections, threaded conical surface sections and sealing step sections from outside to inside. And a layer of uniform and compact oily heat insulation coating is sprayed on the surface of the heat insulation spraying section. A plurality of heat dissipation points inside and outside the tubing coupling are subjected to heat preservation and anti-corrosion treatment, the heat preservation performance of the coupling is improved, meanwhile, the anti-corrosion performance of underground work is improved, and the service life is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas field exploitation, in particular to a composite oil pipe coupling with anti-corrosion and heat-insulating properties. Background Art

[0002] At present, with the continuous advancement of oil and gas field development, most oil fields are facing the problem of increasingly high viscosity of crude oil. Due to the deep well and thick oil, the heat loss during steam injection and oil production is serious. In actual use, the oil pipe is connected by couplings, and the connection and insulation effect of the coupling directly affect the insulation effect of the wellbore.

[0003] For example, a Chinese invention patent with the authorization announcement number CN101832108B discloses a vacuum oil pipe coupling, including a coupling body and an outer sleeve, the coupling body is cylindrical, and the inner surface of the coupling body is provided with tapered holes with a larger outer surface and a smaller inner surface at both ends, and the inner surface of the tapered hole is provided with threads, wherein the outer sleeve is sleeved on the outer surface of the coupling body, and a closed vacuum layer is provided between the outer surface of the coupling body and the inner surface of the outer sleeve. This scheme enhances the thermal insulation performance of the vacuum oil pipe coupling by sleeved the outer sleeve on the outer surface of the coupling body and forming a closed vacuum layer in the gap between the coupling body and the outer sleeve. When the coupling is used, two vacuum composite thermal insulation pipes are respectively screwed into the threaded tapered holes at both ends of the inner hole of the coupling, and the threaded tapered holes enhance the sealing performance between the coupling and the vacuum composite thermal insulation pipe.

[0004] However, the thermal insulation performance of the oil pipe coupling in this solution is poor, and there is a hidden danger of insufficient strength; in addition, due to the harsh underground mining conditions, there are a large number of corrosive substances inside and outside the oil pipe, which cause serious corrosion to the steel oil pipe and coupling, further reducing the thermal insulation performance, and also shortening the service life of the oil pipe and coupling. The thermal insulation effect of the oil pipe coupling in the prior art is average, there are multiple heat loss points, and the underground corrosion protection of the coupling is not considered.

[0005] Therefore, there is an urgent need for a composite oil pipe coupling with anti-corrosion and heat-insulating properties. Utility Model Content

[0006] In order to overcome the problems existing in the prior art, the utility model aims to provide a composite oil pipe coupling with anti-corrosion and heat-insulating properties, which solves the problems that the current oil pipe coupling has insufficient heat-insulating properties and the coupling is prone to corrosion.

[0007] To achieve the above purpose, the utility model provides the following technical solutions: a composite oil pipe coupling with anti-corrosion and heat-insulating properties, comprising a coupling inner tube, a hydrogen-absorbing coating, a heat-insulating layer and a coupling outer tube, wherein the coupling inner tube is cylindrical, the hydrogen-absorbing coating is coated on the outer wall surface of the coupling inner tube; the heat-insulating layer is coated on the outer wall of the hydrogen-absorbing coating; the coupling outer tube is cylindrical and sleeved on the outer wall surface of the heat-insulating layer, and the outer wall surface of the coupling outer tube is provided with a laser cladding coating. The laser cladding coating is a layer of anti-corrosion, anti-sulfur and erosion-resistant coating with high hardness processed by laser cladding process;

[0008] The inner hole cross section of the inner tube of the coupling is symmetrically stepped, and the inner hole of the inner tube of the coupling is a thermal insulation spraying section, a threaded cone section and a sealing platform section from the outside to the inside at the ports at both ends; the surface of the thermal insulation spraying section is sprayed with a layer of uniform and dense oily thermal insulation coating. The oily thermal insulation coating can be an oily thermal insulation coating including mineral fiber, organic fiber, filler and adhesive. The temperature resistance of the oily thermal insulation coating is above 500°C, and the thermal conductivity of the oily thermal insulation coating is 0.3-0.5W / (m°C). It can resist chemicals and has corrosion resistance.

[0009] The utility model is further configured as follows: flanges are arranged at the outer surface edges of the two ends of the inner tube of the coupling, and the hydrogen absorption coating and the thermal insulation layer are arranged between the flanges on the outer surfaces of the two ends of the inner tube of the coupling.

[0010] The utility model is further configured as follows: the upper end surface of the thermal insulation layer is flush with the upper end surface of the flange, the thermal insulation layer adopts SiO2 aerogel, and the thermal conductivity of the thermal insulation layer ranges from 0.3 to 0.4 W / (m°C).

[0011] The utility model is further configured as follows: the thread groove of the thread cone surface section is coated with heat-insulating lubricating oil.

[0012] The utility model is further configured as follows: the coupling outer tube and the coupling inner tube are welded at flanges at both ends of the coupling inner tube.

[0013] The utility model is further configured as follows: the surface of the sealing platform stage is coated with an anti-corrosion layer, and when the oil pipe is installed, the two side surfaces of the sealing platform stage are in close contact with the oil pipes on both sides respectively.

[0014] The utility model is further configured as follows: the thickness of the hydrogen absorption coating is 3 mm.

[0015] The utility model is further configured as follows: the laser cladding coating is a nickel-based alloy layer with a thickness range of 3-6 mm. The laser cladding coating adopts a laser cladding device to feed nickel-based alloy powder of the same material as the outer tube of the coupling into a laser molten pool to form a uniform and dense anti-corrosion, anti-sulfur and wear-resistant laser cladding layer on the processed surface.

[0016] In summary, the beneficial effects of the above technical solution of the utility model are as follows:

[0017] 1. The oil pipe coupling provided by the utility model adopts a composite form of inner and outer coatings of multiple layers of heat insulation materials, including a hydrogen absorption coating, a heat preservation layer, a coupling outer tube and a laser cladding coating, which significantly improves the heat preservation performance of the oil pipe coupling.

[0018] 2. The multi-layer composite structure of the tubing coupling ensures high strength. At the same time, the laser cladding coating on the surface enhances the wear resistance of the tubing coupling, increases the working life of the tubing coupling, and is conducive to improving the operating efficiency of oil and gas fields.

[0019] 3. The contact surface between the inner hole and the wall of the tubing coupling is sprayed with heat-insulating and anti-corrosion oily heat-insulating coating, and a nickel-based alloy layer is clad on the outer surface to enhance the corrosion resistance of the tubing coupling underground. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 This is a cross-sectional view of the composite oil pipe coupling described in an embodiment of the utility model.

[0022] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0023] Figure 3 This is a three-dimensional cross-sectional view of the composite oil pipe coupling described in an embodiment of the utility model.

[0024] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0025] 1. Coupling inner tube; 2. Hydrogen absorption coating; 3. Insulation layer; 4. Coupling outer tube; 5. Laser cladding coating; 101. Flange; 102. Thermal insulation spraying section; 103. Threaded cone section; 104. Sealing platform stage. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the technical solution of the present invention, the following is a clear and complete description of the technical solution of the present invention in conjunction with the drawings of the present invention. Based on the embodiments of the present invention, other similar embodiments obtained by ordinary technicians in the field without creative work should all fall within the scope of protection of the present invention. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", etc., are only referenced to the directions of the drawings. Therefore, the directional words used are used to illustrate rather than limit the creation of the present invention.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0028] The utility model is further described below in conjunction with the accompanying drawings and preferred embodiments.

[0029] Example:

[0030] like Figure 1-Figure 3 As shown, it is a preferred embodiment of the utility model, a composite oil pipe coupling with anti-corrosion and heat-insulating properties, comprising a coupling inner tube 1, a hydrogen absorption coating 2, a heat-insulating layer 3, and a coupling outer tube 4. The coupling inner tube 1 is cylindrical, and flanges 101 are provided at the edges of the outer surfaces of both ends of the coupling inner tube 1. The inner hole cross-section of the coupling inner tube 1 is stepped, which is sequentially a heat-insulating spray section 102, a threaded cone section 103 with a larger outer portion and a smaller inner portion, and a sealing platform section 104.

[0031] The hydrogen absorption coating 2 is coated on the outer wall of the inner tube 1 of the coupling; the thermal insulation layer 3 is between the flanges 101 at both end faces and is flush with the flanges 101, and the thermal insulation layer 3 is coated on the outer wall of the hydrogen absorption coating 2. The outer tube 4 of the coupling is cylindrical and sleeved on the outer wall of the thermal insulation layer 3. The outer wall of the outer tube 4 of the coupling is provided with a laser cladding coating 5; the laser cladding coating 5 is a layer of anti-corrosion, anti-sulfur and erosion-resistant coating with high hardness processed by laser cladding technology; the thermal insulation spraying section 102 is sprayed with a uniform and dense layer of oil-based thermal insulation coating.

[0032] The oily thermal insulation coating used in this embodiment is composed of mineral fiber, organic fiber, filler and adhesive, has a temperature resistance of more than 500°C, a thermal conductivity of 0.3-0.5W / (m·°C), can resist chemical substances and has corrosion resistance.

[0033] The thread groove of the thread cone section 103 is coated with heat-insulating lubricating oil. The surface of the sealing platform stage 104 is coated with an anti-corrosion layer. When the oil pipe is installed, the two side surfaces of the sealing platform stage 104 are in close contact with the installed oil pipes on both sides.

[0034] like Figure 2 As shown, flanges 101 are provided at the outer surface edges of both ends of the coupling inner tube 1, the hydrogen absorption coating 2 and the thermal insulation layer 3 are provided between the flanges 101 at both end surfaces of the coupling inner tube 1, and the height of the thermal insulation layer 3 is flush with the flanges 101. The coupling outer tube 4 and the coupling inner tube 1 are welded at the flanges 101 at both ends of the coupling inner tube 1.

[0035] The material of the thermal insulation layer 3 is SiO2 aerogel, and the thermal conductivity is 0.3-0.4 W / (m·°C).

[0036] The hydrogen absorbing coating 2 is coated on the outer wall surface of the coupling inner tube 1 and has a thickness of 3 mm.

[0037] The laser cladding coating 5 uses a laser cladding device to feed nickel-based alloy powder of the same material as the coupling outer tube 4 into a laser molten pool, forming a uniform, dense, corrosion-resistant, sulfur-resistant, and wear-resistant laser cladding layer on the processed surface with a thickness of 3-6 mm.

[0038] In summary, the utility model performs thermal insulation and anti-corrosion treatment on multiple heat dissipation points inside and outside the oil pipe coupling 1, thereby improving the thermal insulation performance of the coupling, while also improving the corrosion resistance of underground work and extending the working life.

[0039] Finally, it should be noted that the above content is only used to illustrate the technical solution of the utility model, rather than to limit the protection scope of the utility model. Simple modifications or equivalent substitutions of the technical solution of the utility model by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the utility model.

Claims

1. A composite oil pipe coupling with anti-corrosion and heat-insulating properties, characterized in that: It comprises a coupling inner tube, a hydrogen absorbing coating, a thermal insulation layer and a coupling outer tube, wherein the coupling inner tube is cylindrical, the hydrogen absorbing coating is coated on the outer wall surface of the coupling inner tube; the thermal insulation layer is coated on the outer wall of the hydrogen absorbing coating; the coupling outer tube is cylindrical and sleeved on the outer wall surface of the thermal insulation layer, and the outer wall surface of the coupling outer tube is provided with a laser cladding coating; The inner hole cross section of the inner tube of the coupling is symmetrically stepped, and the inner hole of the inner tube of the coupling is composed of a thermal insulation spray section, a threaded cone section and a sealing platform section from the outside to the inside at the ports at both ends; a layer of uniform and dense oil-based thermal insulation coating is sprayed on the surface of the thermal insulation spray section.

2. The composite oil pipe coupling with anti-corrosion and heat-insulating properties according to claim 1, characterized in that: Flanges are arranged at the outer surface edges of the two ends of the inner pipe of the coupling, and the hydrogen absorption coating and the heat insulation layer are arranged between the flanges on the outer surfaces of the two ends of the inner pipe of the coupling.

3. The composite oil pipe coupling with anti-corrosion and heat-insulating properties according to claim 2, characterized in that: The upper end surface of the thermal insulation layer is flush with the upper end surface of the flange. The thermal insulation layer is made of SiO2 aerogel with a thermal conductivity of 0.3-0.4W / (m°C).

4. The composite oil pipe coupling with anti-corrosion and heat-insulating properties according to claim 1, characterized in that: The thread groove of the thread cone surface section is coated with heat-insulating lubricating oil.

5. The composite oil pipe coupling with anti-corrosion and heat-insulating properties according to claim 1, characterized in that: The surface of the sealing platform stage is coated with an anti-corrosion layer; when the oil pipe is installed, the two side surfaces of the sealing platform stage are in close contact with the oil pipes on both sides respectively.

6. The composite oil pipe coupling with anti-corrosion and heat-insulating properties according to claim 2, characterized in that: The coupling outer tube and the coupling inner tube are welded at flanges at both ends of the coupling inner tube.

7. The composite oil pipe coupling with anti-corrosion and heat-insulating properties according to claim 1, characterized in that: The thickness of the hydrogen absorbing coating is 3 mm.

8. The composite oil pipe coupling with anti-corrosion and heat-insulating properties according to claim 1, characterized in that: The laser cladding coating is a nickel-based alloy layer with a thickness ranging from 3 to 6 mm.

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